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The graphene-MnO2-polyaniline (rGO-MnO2-PAn) ternary composites were prepared via in situ chemical oxidative polymerization of polyaniline on the MnO2 decorated graphene sheets. The graphene sheets were treated with KMnO4 in a water-ethylene glycol system using the hydrothermal method to complete the loading of MnO2 on the graphene sheets, while the graphene oxide (GO) sheets were hydrothermally reduced to reduced graphene oxide (rGO). The glycol was introduced as a reductant to react with MnO4(-), and GO was protected from consumption in the process of deposition of MnO2. The structures and morphologies of the resulting ternary composites are characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical properties of the composites as potential electrode materials for supercapacitors were investigated using different electrochemical techniques including cyclic voltammetry (CV), galvanostatic charge-discharge, and electrochemical impedance spectroscopy (EIS). The specific capacitance of a rGO-MnO2-PAn composite electrode was 395 F g(-1) at 10 mA cm(-2) in 1 M H2SO4 solution. The composites displayed good cycle stability retaining 92% of their original specific capacitance after 1200 cycles by continuous cyclic voltammetric scans at 100 mV s(-1).

Multifunctional superparamagnetic attapulgite/Fe3O4/polyaniline (APT/Fe3O4/PANI) nanocomposites have been fabricated by a one-pot process using Fe(iii) as the oxidant for aniline and the precursor of Fe3O4 in the presence of attapulgite.

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The superparamagnetic multilayer hybrid hollow microspheres have been fabricated using the layer-by-layer assembly technique by the electrostatic interaction between the polyelectrolyte cation chitosan (CS) and the hybrid anion citrate modified ferroferric oxide nanoparticles (Fe 3 O 4 -CA) onto the sacrificial polystyrene sulfonate microspheres templates after etching the templates by dialysis. The saturation magnetization and magnetite contents of the superparamagnetic multilayer hybrid hollow microspheres were 32.46 emu/g and 51.3%, respectively. The hybrid hollow microspheres showed pH-sensitive characteristics. The adsorption and release of the basic dye (methylene blue) were applied to investigate the interaction between the amino groups of CS and the carboxyl groups of the Fe 3 O 4 -CA nanoparticles in different pH media. The superparamagnetic pH-sensitive multilayer hybrid hollow microspheres are expected to be used for the targeted controlled release of drugs or in diagnostics. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3135-3144, 2010 KEYWORDS: hybrid hollow microspheres; layer-by-layer assembly; pH sensitive; superparamagnetic; targeted controlled releaseRecently, surface-charged nanoparticles have been used for the fabrication of the multilayer hybrid hollow microspheres.

Using graphene as adsorbent for removal of pollutants from polluted water is commonly recognized to be costly because the graphene is usually produced by a very complex process. Herein, a simple and eco-friendly method was employed to fabricate efficient superparamagnetic graphene/polyaniline/Fe3O4 nanocomposites for removal of dyes. The exfoliation of graphite as nanosheets and the functionalization of nanosheets with polyaniline and Fe3O4 nanoparticles were simultaneously achieved via a one-pot reaction process combining the intercalation polymerization of aniline and the co-precipitation of the residual Fe3+ and the generated Fe2+. The obtained graphene/polyaniline/Fe3O4 nanocomposites exhibited excellent adsorption performance for Congo red, even in the presence of Brilliant green. The adsorption kinetics and adsorption isotherms were well fitted with pseudo second-order kinetic model and Langmuir isotherm model, respectively. In a word, this method is simple and industrially feasible, which provides a new approach to fabricate highly efficient graphene-based adsorbents on large scale for removal of dyes. In addition, it also can be used to exfoliate other two-dimensional materials, such as boron nitride, carbon nitride and MoS2 for a range of possible applications.

Attapulgite/carbon nanocomposites were fabricated via one-step calcination of the spent bleaching earth served as adsorbents for the efficient removal of heavy metal ions (Cu(II), Pb(II) and Cd(II)). The as-prepared nanocomposites were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, thermogravimetric analysis and Brunauer−Emmett− Teller techniques. The process parameters affecting the adsorption behaviors such as initial pH, calcination temperature, contact time and initial concentration of heavy metal ions were systematically investigated. The results indicated that the attapulgite/carbon nanocomposites derived from the low-cost available carbon precursors exhibited high adsorption capacity within a wide pH range, and the faster equilibrium was achieved at lower concentration. In addition, the adsorbed Cu(II), Pb(II) and Cd(II) can be partially desorbed using 0.1 mol/L HCl as the desorbing agent, rendering the as-prepared adsorbent good readsorption ability, especially for the removal of Cu(II). Using the adsorption of Cd(II) as an example, it has been confirmed that the electrostatic interaction, cation exchange and surface complexation between Cd(II) and functional groups on the attapulgite/carbon nanocomposites were the dominant mechanisms according to the results of the adsorption studies and XPS analysis. Furthermore, this research develops a feasible route for the application of the spent bleaching earth in the wastewater treatment.